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CHEMICAL ENGINEERING (188 journals)                     

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AATCC Journal of Research     Full-text available via subscription   (Followers: 4)
ACS Sustainable Chemistry & Engineering     Hybrid Journal  
Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials     Hybrid Journal   (Followers: 4)
Acta Polymerica     Hybrid Journal   (Followers: 7)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 6)
Advanced Chemical Engineering Research     Open Access   (Followers: 27)
Advanced Powder Technology     Hybrid Journal   (Followers: 13)
Advances in Applied Ceramics     Hybrid Journal   (Followers: 4)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 23)
Advances in Chemical Engineering and Science     Open Access   (Followers: 50)
Advances in Polymer Technology     Hybrid Journal   (Followers: 12)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Annual Review of Analytical Chemistry     Full-text available via subscription   (Followers: 9)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 9)
Anti-Corrosion Methods and Materials     Hybrid Journal   (Followers: 6)
Applied Petrochemical Research     Open Access   (Followers: 2)
Asia-Pacific Journal of Chemical Engineering     Hybrid Journal   (Followers: 7)
Biochemical Engineering Journal     Hybrid Journal   (Followers: 13)
Biofuel Research Journal     Open Access   (Followers: 3)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 11)
Brazilian Journal of Chemical Engineering     Open Access   (Followers: 3)
Bulletin of Chemical Reaction Engineering & Catalysis     Open Access   (Followers: 2)
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 3)
Carbohydrate Polymers     Hybrid Journal   (Followers: 7)
Catalysts     Open Access   (Followers: 6)
ChemBioEng Reviews     Full-text available via subscription  
Chemical and Engineering News     Free   (Followers: 11)
Chemical and Materials Engineering     Open Access   (Followers: 6)
Chemical and Petroleum Engineering     Hybrid Journal   (Followers: 10)
Chemical and Process Engineering     Open Access   (Followers: 20)
Chemical and Process Engineering Research     Open Access   (Followers: 18)
Chemical Engineering & Technology     Hybrid Journal   (Followers: 32)
Chemical Engineering and Processing: Process Intensification     Hybrid Journal   (Followers: 17)
Chemical Engineering and Science     Open Access   (Followers: 13)
Chemical Engineering Communications     Hybrid Journal   (Followers: 12)
Chemical Engineering Journal     Hybrid Journal   (Followers: 27)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 21)
Chemical Engineering Research Bulletin     Open Access   (Followers: 8)
Chemical Engineering Science     Hybrid Journal   (Followers: 20)
Chemical Geology     Hybrid Journal   (Followers: 14)
Chemical Papers     Hybrid Journal   (Followers: 2)
Chemical Product and Process Modeling     Hybrid Journal   (Followers: 3)
Chemical Reviews     Full-text available via subscription   (Followers: 129)
Chemical Society Reviews     Full-text available via subscription   (Followers: 39)
Chemical Technology     Open Access   (Followers: 11)
ChemInform     Hybrid Journal   (Followers: 6)
Chemistry & Industry     Hybrid Journal   (Followers: 3)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry of Materials     Full-text available via subscription   (Followers: 148)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
ChemSusChem     Hybrid Journal   (Followers: 5)
Chinese Chemical Letters     Full-text available via subscription   (Followers: 3)
Chinese Journal of Chemical Engineering     Full-text available via subscription   (Followers: 3)
Chinese Journal of Chemical Physics     Hybrid Journal   (Followers: 1)
Coke and Chemistry     Hybrid Journal   (Followers: 1)
Coloration Technology     Hybrid Journal  
Computational Biology and Chemistry     Hybrid Journal   (Followers: 9)
Computer Aided Chemical Engineering     Full-text available via subscription   (Followers: 1)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 9)
CORROSION     Full-text available via subscription   (Followers: 19)
Corrosion Engineering, Science and Technology     Hybrid Journal   (Followers: 35)
Corrosion Reviews     Hybrid Journal   (Followers: 3)
Crystal Research and Technology     Hybrid Journal   (Followers: 5)
Current Opinion in Chemical Engineering     Open Access   (Followers: 7)
Education for Chemical Engineers     Hybrid Journal   (Followers: 4)
Eksergi     Open Access  
Emerging Trends in Chemical Engineering     Full-text available via subscription  
European Polymer Journal     Hybrid Journal   (Followers: 41)
Fibers and Polymers     Full-text available via subscription   (Followers: 4)
Fluorescent Materials     Open Access   (Followers: 1)
Focusing on Modern Food Industry     Open Access   (Followers: 2)
Frontiers of Chemical Science and Engineering     Hybrid Journal   (Followers: 1)
Gels     Open Access  
Geochemistry International     Hybrid Journal   (Followers: 2)
Handbook of Powder Technology     Full-text available via subscription   (Followers: 3)
Heat Exchangers     Open Access   (Followers: 1)
High Performance Polymers     Hybrid Journal  
Hungarian Journal of Industry and Chemistry     Open Access  
Indian Chemical Engineer     Hybrid Journal   (Followers: 5)
Indian Journal of Chemical Technology (IJCT)     Open Access   (Followers: 9)
Indonesian Journal of Chemical Science     Open Access   (Followers: 1)
Industrial & Engineering Chemistry     Full-text available via subscription   (Followers: 9)
Industrial & Engineering Chemistry Research     Full-text available via subscription   (Followers: 20)
Industrial Chemistry Library     Full-text available via subscription   (Followers: 3)
Industrial Gases     Open Access  
Info Chimie Magazine     Full-text available via subscription   (Followers: 3)
International Journal of Chemical and Petroleum Sciences     Open Access   (Followers: 2)
International Journal of Chemical Engineering     Open Access   (Followers: 6)
International Journal of Chemical Reactor Engineering     Hybrid Journal   (Followers: 2)
International Journal of Chemical Technology     Open Access   (Followers: 5)
International Journal of Chemoinformatics and Chemical Engineering     Full-text available via subscription   (Followers: 2)
International Journal of Food Science     Open Access   (Followers: 3)
International Journal of Industrial Chemistry     Open Access  
International Journal of Polymeric Materials     Hybrid Journal   (Followers: 5)
International Journal of Science and Engineering     Open Access   (Followers: 4)
International Journal of Waste Resources     Open Access   (Followers: 3)
Journal of Chemical Engineering & Process Technology     Open Access   (Followers: 4)
Journal of Applied Crystallography     Hybrid Journal   (Followers: 5)
Journal of Applied Electrochemistry     Hybrid Journal   (Followers: 10)
Journal of Applied Polymer Science     Hybrid Journal   (Followers: 105)
Journal of Biomaterials Science, Polymer Edition     Hybrid Journal   (Followers: 9)
Journal of Bioprocess Engineering and Biorefinery     Full-text available via subscription  
Journal of Chemical & Engineering Data     Full-text available via subscription   (Followers: 10)
Journal of Chemical and Biological Interfaces     Full-text available via subscription   (Followers: 1)
Journal of Chemical Ecology     Hybrid Journal   (Followers: 6)
Journal of Chemical Engineering     Open Access   (Followers: 13)
Journal of Chemical Engineering and Materials Science     Open Access   (Followers: 2)
Journal of Chemical Science and Technology     Open Access   (Followers: 4)
Journal of Chemical Sciences     Partially Free   (Followers: 17)
Journal of Chemical Technology & Biotechnology     Hybrid Journal   (Followers: 10)
Journal of Chemical Theory and Computation     Full-text available via subscription   (Followers: 14)
Journal of CO2 Utilization     Hybrid Journal   (Followers: 2)
Journal of Crystallization Process and Technology     Open Access   (Followers: 7)
Journal of Environmental Chemical Engineering     Hybrid Journal   (Followers: 3)
Journal of Food Measurement and Characterization     Hybrid Journal  
Journal of Food Processing & Technology     Open Access  
Journal of Fuel Chemistry and Technology     Full-text available via subscription   (Followers: 4)
Journal of Geochemical Exploration     Hybrid Journal   (Followers: 1)
Journal of Industrial and Engineering Chemistry     Hybrid Journal   (Followers: 1)
Journal of Information Display     Hybrid Journal  
Journal of Inorganic and Organometallic Polymers and Materials     Partially Free   (Followers: 7)
Journal of Modern Chemistry & Chemical Technology     Full-text available via subscription   (Followers: 2)
Journal of Molecular Catalysis A: Chemical     Hybrid Journal   (Followers: 5)
Journal of Non-Crystalline Solids     Hybrid Journal   (Followers: 7)
Journal of Organic Semiconductors     Open Access   (Followers: 4)
Journal of Physics and Chemistry of Solids     Hybrid Journal   (Followers: 5)
Journal of Polymer and Biopolymer Physics Chemistry     Open Access   (Followers: 4)
Journal of Polymer Engineering     Hybrid Journal   (Followers: 8)
Journal of Polymer Research     Hybrid Journal   (Followers: 6)
Journal of Polymer Science Part C : Polymer Letters     Hybrid Journal   (Followers: 5)
Journal of Polymers     Open Access   (Followers: 2)
Journal of Polymers and the Environment     Hybrid Journal   (Followers: 1)
Journal of Pure and Applied Chemistry Research     Open Access   (Followers: 1)
Journal of the American Chemical Society     Full-text available via subscription   (Followers: 249)
Journal of the Bangladesh Chemical Society     Open Access  
Journal of the Brazilian Chemical Society     Open Access   (Followers: 2)
Journal of The Institution of Engineers (India) : Series E     Hybrid Journal   (Followers: 1)
Journal of the Pakistan Institute of Chemical Engineers     Open Access   (Followers: 1)
Journal of the Taiwan Institute of Chemical Engineers     Hybrid Journal   (Followers: 2)
Journal of Water Chemistry and Technology     Hybrid Journal   (Followers: 8)
Jurnal Bahan Alam Terbarukan     Open Access  
Jurnal Inovasi Pendidikan Kimia     Open Access  
Jurnal Reaktor     Open Access  
Jurnal Teknologi Dan Industri Pangan     Open Access   (Followers: 1)
Korean Journal of Chemical Engineering     Hybrid Journal   (Followers: 3)
Main Group Metal Chemistry     Hybrid Journal   (Followers: 1)
Materials Chemistry and Physics     Full-text available via subscription   (Followers: 14)
Materials Science and Applied Chemistry     Open Access  
Materials Sciences and Applied Chemistry     Full-text available via subscription  
Modern Chemistry & Applications     Open Access  
Molecular Imprinting     Open Access  
Nanocontainers     Open Access  
Nanofabrication     Open Access  
Noise Control Engineering Journal     Full-text available via subscription   (Followers: 2)
Ochrona Srodowiska i Zasobów Naturalnych : Environmental Protection and Natural Resources     Open Access  
Petroleum Chemistry     Hybrid Journal   (Followers: 1)
Physics and Chemistry of Glasses - European Journal of Glass Science and Technology Part B     Full-text available via subscription   (Followers: 3)
Plasma Processes and Polymers     Hybrid Journal  
Plasmas and Polymers     Hybrid Journal  
Polymer     Hybrid Journal   (Followers: 105)
Polymer Bulletin     Hybrid Journal   (Followers: 7)
Polymer Composites     Hybrid Journal   (Followers: 14)
Polyolefins Journal     Open Access  
Powder Technology     Hybrid Journal   (Followers: 12)
Recyclable Catalysis     Open Access   (Followers: 1)
Research on Chemical Intermediates     Hybrid Journal  
Reviews in Chemical Engineering     Hybrid Journal   (Followers: 5)
Revista Cubana de Química     Open Access  
Revista ION     Open Access  
Revista Mexicana de Ingeniería Química     Open Access  
Rubber Chemistry and Technology     Full-text available via subscription   (Followers: 2)
Russian Chemical Bulletin     Hybrid Journal   (Followers: 2)
Russian Journal of Applied Chemistry     Hybrid Journal   (Followers: 1)
Science and Engineering of Composite Materials     Hybrid Journal   (Followers: 58)
Solid Fuel Chemistry     Hybrid Journal  
South African Journal of Chemical Engineering     Open Access   (Followers: 2)
South African Journal of Chemistry     Open Access   (Followers: 2)
Surface Engineering and Applied Electrochemistry     Hybrid Journal   (Followers: 5)
Sustainable Chemical Processes     Open Access   (Followers: 2)
Synthesis Lectures on Chemical Engineering and Biochemical Engineering     Full-text available via subscription  
The Canadian Journal of Chemical Engineering     Hybrid Journal   (Followers: 3)
The Chemical Record     Hybrid Journal   (Followers: 1)
Theoretical Foundations of Chemical Engineering     Hybrid Journal   (Followers: 2)
Transition Metal Chemistry     Hybrid Journal   (Followers: 2)
Transylvanian Review of Systematical and Ecological Research     Open Access  
Visegrad Journal on Bioeconomy and Sustainable Development     Open Access   (Followers: 1)
Zeitschrift für Naturforschung B : A Journal of Chemical Sciences     Open Access   (Followers: 1)


Journal Cover Chemical Engineering Science
  [SJR: 1.073]   [H-I: 135]   [20 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0009-2509
   Published by Elsevier Homepage  [3038 journals]
  • Frequency domain constrained optimization of boundary control action for
           maximization of mixing in channel flow
    • Authors: Pesila Ratnayake; Jie Bao
      Pages: 1 - 20
      Abstract: Publication date: 2 February 2017
      Source:Chemical Engineering Science, Volume 158
      Author(s): Pesila Ratnayake, Jie Bao
      Improving mixing is one of the important goals in flow control, e.g., to decrease concentration polarization in membrane systems to reduce fouling. As with many distributed parameter systems, fluid flow can be controlled using boundary value manipulation. Fluid manipulation using electro-osmosis is studied in this work, where several cylindrical electrodes are used to create multiple spatially non-uniform time-varying electric fields. The proposed approach converts the distributed parameter system into an infinite-dimensional system by spatial and spectral discretization. A virtual output variable is constructed to allow the optimization of a mixing objective function to be conducted using frequency response analysis, with consideration of the constraints of conservation of charge. The solution obtained in this paper is the input profile that provides the greatest achievable ratio of time-average dissipation function to time-average input energy satisfying the input constraints.

      PubDate: 2016-10-04T09:54:44Z
      DOI: 10.1016/j.ces.2016.09.013
      Issue No: Vol. 158 (2016)
  • Numerical simulation of separation process for enhancing fine particle
           removal in tertiary sedimentation tank mounting adjustable baffle
    • Authors: Hong Guo; Seo Jin Ki; Seungjae Oh; Young Mo Kim; Semyung Wang; Joon Ha Kim
      Pages: 21 - 29
      Abstract: Publication date: 2 February 2017
      Source:Chemical Engineering Science, Volume 158
      Author(s): Hong Guo, Seo Jin Ki, Seungjae Oh, Young Mo Kim, Semyung Wang, Joon Ha Kim
      The presence of flow control devices and/or obstacles in the fluid flow such as baffles and spacers complicates the solid-fluid mixing pattern, which remains difficult to describe by classical analytical solutions. In this study, the removal of fine particles in a tertiary sedimentation tank mounting an adjustable baffle was investigated using the computational fluid dynamics code-COMSOL. The solid-fluid motion was solved by consecutively applying the equations of the continuity and momentum using the finite element method. The experiment was conducted by the sedimentation tank with the adjustable baffle inclined at 30° in a pilot scale plant. It's used as the reference data set for numerical simulations that were run on a 2-dimensional domain by modifying the configuration settings of angles for an adjustable baffle (i.e., 30°, 45°, and 60°) and without one. Results showed that the simulation results matched well with the experimental data for an adjustable baffle at 30° (NSE=0.97). The sedimentation tank with the adjustable baffle at different angles had a lower overflow rate (in the area of flow rebound) and mixing intensity (in the area of flow curve) than without one, eventually leading to enhanced particle removal efficiency. This tendency became more pronounced as the particle motion stabilized over time. The sedimentation tank mounting the adjustable baffle at 30° provided the best settling efficiency among the four different flow patterns. However, the conventional index that represents the mixing properties did not correctly address their relative efficiency for fine particle removal. Therefore, a numerical simulation tailored to a given geometry should be conducted to fully elucidate the fluid dynamics in the sedimentation tank with complex devices or obstacles.

      PubDate: 2016-10-04T09:54:44Z
      DOI: 10.1016/j.ces.2016.09.022
      Issue No: Vol. 158 (2016)
  • Catalytic self-sustaining combustion of the alkanes with Pt/ZSM-5 packed
           bed in a microscale tube
    • Authors: Weijuan Yang; Yefeng Wang; Junhu Zhou; Jingsong Zhou; Zhihua Wang; Kefa Cen
      Pages: 30 - 36
      Abstract: Publication date: 2 February 2017
      Source:Chemical Engineering Science, Volume 158
      Author(s): Weijuan Yang, Yefeng Wang, Junhu Zhou, Jingsong Zhou, Zhihua Wang, Kefa Cen
      Experimental studies on the combustion of methane, propane and n-octane with Pt/ZSM-5 packed bed were performed in a tube with a diameter of 4mm in order to acquire several performance indicators, including the self-sustaining combustion limit, conversion efficiency, and heat output among others. The increase of equivalence ratio (Φ) extended the velocity limits (v) of self-sustaining combustion in varying degrees for the three fuels under study. Methane presented a relatively narrow self-sustaining combustion region, low conversion (≤25%), high CO selectivity (5–11%) and low tube wall temperature (<250°C) at Φ=1.0 and v=0.8–1.4m/s. The catalytic reactivity for methane oxidization over Pt/ZSM-5 was highly activated at temperatures over 455°C, this being responsible for the methane combustion performance. In the case of propane combustion processes, a homogenous reaction occurred downstream the catalyst section and led to high conversion. Under Φ=1.0 and v=0.8–1.4m/s conditions, propane conversion was higher than 45% while the CO2 selectivity remained over 96%. n-Octane showed similar combustion performance than propane, with a little backward gap detected. The released heat by fuel combustion increased in the order: methane, n-octane, and propane, with the maximum heat values being 12, 19, and 32W, respectively. Propane was suitable for micro combustion with the catalyst, as a result of the low catalytic ignition temperature (124°C) and high catalytic reactivity.

      PubDate: 2016-10-10T15:18:25Z
      DOI: 10.1016/j.ces.2016.09.027
      Issue No: Vol. 158 (2016)
  • Xylose enhances furfural tolerance in Candida tropicalis by improving NADH
    • Authors: Shizeng Wang; Zijun He; Qipeng Yuan
      Pages: 37 - 40
      Abstract: Publication date: 2 February 2017
      Source:Chemical Engineering Science, Volume 158
      Author(s): Shizeng Wang, Zijun He, Qipeng Yuan
      Furfural is one of the typical inhibitors present in hemicellulose hydrolysate. Furfural is harmful to cell growth and biofuel production in microbes. As one of the microbes that could use xylose in hemicellulose hydrolysate, Candia. tropicalis shows a promising potential for metabolic engineering to produce biofuels and value-added chemicals. In this study, we found that the rate of furfural degradation and half maximal inhibitory concentration for furfural of C. tropicalis in xylose medium increased 1.68-fold and 1.19-fold, respectively, compared with those in glucose medium, indicating that C. tropicalis obtained better furfural tolerance in xylose medium. The dehydrogenation of xylitol, which produces coenzyme NADH, promotes the recycle of NAD+ and facilitates the reduction of furfural. This study provides important information for metabolic regulation and metabolic engineering of efficient lignocellulose fermentation strains.
      Graphical abstract image

      PubDate: 2016-10-10T15:18:25Z
      DOI: 10.1016/j.ces.2016.09.026
      Issue No: Vol. 158 (2016)
  • Optimized polybutylene terephthalate powders for selective laser beam
    • Authors: Jochen Schmidt; Marius Sachs; Stephanie Fanselow; Meng Zhao; Stefan Romeis; Dietmar Drummer; Karl-Ernst Wirth; Wolfgang Peukert
      Pages: 1 - 10
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): Jochen Schmidt, Marius Sachs, Stephanie Fanselow, Meng Zhao, Stefan Romeis, Dietmar Drummer, Karl-Ernst Wirth, Wolfgang Peukert
      Additive manufacturing processes like selective laser beam melting of polymers (LBM) are established for production of prototypes and individualized parts. The transfer to serial production currently is hindered by the limited availability of polymer powders with good processability. Within this contribution the effect of powder properties, such as particle size, shape and flowability on the processability in LBM and their influence on device quality is exemplified for polybutylene terephthalate (PBT) materials. A process chain for the production of spherical polymer microparticles has been developed to obtain PBT powder materials. The process chain consists of three steps: first, polymer microparticles are produced by wet grinding. Second, the particle shape is engineered by rounding in a heated downer reactor to improve the flowability of the product. Third, a further improvement of flowability of the still cohesive spherical PBT particles is realized by dry coating with fumed silica. Moreover, properties of the PBT powders obtained along the process chain are thoroughly characterized with respect to structure and crystallinity by infrared spectroscopy, X-ray diffraction and differential scanning calorimetry. The effect of flowability, shape and bulk density on the powders’ processabilities in LBM is assessed by characterization of the quality of thin layers built in a LBM device. It is demonstrated that the device quality is strongly determined by particle properties: powders of good flowability and high bulk density are mandatory to obtain dense devices.
      Graphical abstract image

      PubDate: 2016-09-18T13:44:25Z
      DOI: 10.1016/j.ces.2016.09.009
      Issue No: Vol. 156 (2016)
  • Numerical and experimental investigation of hydrodynamics and light
           transfer in open raceway ponds at various algal cell concentrations and
           medium depths
    • Authors: Hossein Amini; Abolhasan Hashemisohi; Lijun Wang; Abolghasem Shahbazi; Marwan Bikdash; Dukka KC; Wenqiao Yuan
      Pages: 11 - 23
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): Hossein Amini, Abolhasan Hashemisohi, Lijun Wang, Abolghasem Shahbazi, Marwan Bikdash, Dukka KC, Wenqiao Yuan
      A spectral radiation-transport model was integrated with a three dimensional computational fluid dynamics model to simulate the hydrodynamics and light transfer in open raceway ponds (ORPs). The predicted three-dimensional velocity and light intensity agreed well with measured values collected on a lab-scale ORP. However, there was a slight difference in the predicted velocity profiles using two different types of boundaries for the paddlewheel, i.e., the moving zone boundary and inlet velocity boundary, with R 2 values between the predicted and measured velocities of 0.9947 and 0.9838, respectively. The R 2 value between the predicted and measured light intensity was 0.9939. Simulations were further conducted on a large-scale ORP with 100m2 surface area operated at total medium depths of 0.2 and 0.3m, average cell concentration of 0.4g/L, and inlet velocities of 0.1, 0.2 and 0.3m/s from the paddlewheel. The increase of inlet flow velocity from 0.1 to 0.2m/s resulted in a more uniform cell concentration profile. However, when the inlet velocity was further increased from 0.2 to 0.3m/s, there was only a slight increase in the uniformity of the cell concentration. In addition, the simulation results showed that sedimentation of cells more likely occurred at the bottom of the ORP with a total medium depth of 0.2m than at 0.3m at the same inlet velocity. The increase of inlet velocity from the paddlewheel resulted in a uniformly distributed light intensity in the region near the medium surface (e.g., 0.05m depth from the surface) owing to improved mixing. However, owing to a sudden drop in the light intensity after a few centimeters from the medium surface, the cell sedimentation that occurred at the bottom of the ORPs had negligible effects on the light penetration depth in the medium.

      PubDate: 2016-09-18T13:44:25Z
      DOI: 10.1016/j.ces.2016.09.003
      Issue No: Vol. 156 (2016)
  • Carbon dioxide rich microbubble acceleration of biogas production in
           anaerobic digestion
    • Authors: Mahmood K.H. Al-mashhadani; Stephen J. Wilkinson; William B. Zimmerman
      Pages: 24 - 35
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): Mahmood K.H. Al-mashhadani, Stephen J. Wilkinson, William B. Zimmerman
      This paper addresses the use of anaerobic bacteria to convert carbon dioxide to biomethane as part of the biodegradation process of organic waste. The current study utilises gaslift bioreactors with microbubbles generated by fluidic oscillation to strip the methane produced in the gaslift bioreactor. Removal of methane makes its formation thermodynamically more favourable. In addition, intermittent sparging of microbubbles can prevent thermal stratification, maintain uniformity of the pH and increase the intimate contact between the feed and microbial culture with lower energy requirements than traditional mixing. A gaslift bioreactor with microbubble sparging has been implemented experimentally, using a range of carrier gas, culminating in pure carbon dioxide, in the anaerobic digestion process. The results obtained from the experiments show that the methane production rate is approximately doubled with pure carbon dioxide as the carrier gas for intermittent microbubble sparging.
      Graphical abstract image

      PubDate: 2016-09-18T13:44:25Z
      DOI: 10.1016/j.ces.2016.09.011
      Issue No: Vol. 156 (2016)
  • Propylene epoxidation with hydrogen peroxide in acidic conditions
    • Authors: E. Kertalli; L.S. van. Rijnsoever; V. Paunovic; M.F. Neira d'Angelo; J.C. Schouten; T.A. Nijhuis
      Pages: 36 - 43
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): E. Kertalli, L.S. van. Rijnsoever, V. Paunovic, M.F. Neira d'Angelo, J.C. Schouten, T.A. Nijhuis
      In the present work, the epoxidation of propylene with hydrogen peroxide in the presence of acids and halides is studied. The presence of acids and halides is indispensable for increasing the selectivity of the direct synthesis of hydrogen peroxide, the first step of the direct propylene oxide production from hydrogen, oxygen and propylene. Therefore, we focus on the systematic study of the effect of these compounds on the epoxidation of propylene with hydrogen peroxide in prospective of its future integration with hydrogen peroxide in-situ formed. Indeed, the epoxidation of propylene with hydrogen peroxide is the second step of the direct PO synthesis from hydrogen, oxygen and propylene. The acid concentration and type were shown to have an effect on the PO selectivity. Sulphuric and hydrochloric acids, typical compounds used to stabilize the hydrogen peroxide, are not suitable for the direct propylene oxide due to their fast dissociation in the solution. This leads to a fast ring opening reaction of the epoxide. Phosphoric acid was shown to have a much milder effect on the propylene oxide selectivity, therefore being an option for the direct propylene oxide synthesis. Also, the amount of halides (NaBr) needed to stabilize the hydrogen peroxide, does not have an effect on the epoxidation step. Therefore phosphoric acid and NaBr can be implemented in the direct propylene oxide synthesis from hydrogen, oxygen and propylene.

      PubDate: 2016-09-18T13:44:25Z
      DOI: 10.1016/j.ces.2016.09.008
      Issue No: Vol. 156 (2016)
  • Generalized Boltzmann kinetic theory for EMMS-based two-fluid model
    • Authors: Bidan Zhao; Shuyue Li; Junwu Wang
      Pages: 44 - 55
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): Bidan Zhao, Shuyue Li, Junwu Wang
      It has long been recognized that the solid particles in circulating fluidized bed risers are distributed heterogeneously in the form of clusters. In response to this fundamental phenomenon, an EMMS-based two-fluid model has been developed recently from the viewpoint of continuum mechanics, however, its microscopic foundation remains unknown. In this study, the statistical mechanics foundation of EMMS-based two-fluid model was presented using generalized Boltzmann kinetic theory. With respect to the gas phase, a new method was developed by considering the fluctuations at different scales simultaneously, with which we can for the first time derive the correct governing equations of gas phase via kinetic theory, in the sense that both the molecular stress and the Reynolds (or pseudo-Reynolds) stress can be obtained simultaneously, whereas all previous kinetic theory analyses failed to predict the appearance of Reynolds (or pseudo-Reynolds) stress in the momentum conservation equation of gas phase due to the assumption of uniform structure, although it is physically always existent no matter how small the Reynolds number is. In case of particle phase, the generalized Boltzmann equation considering the spatio-temporal variation of the volume, density and velocity of clusters was firstly derived, a set of macroscopic transport equations was then derived in different phase spaces. It was shown that the governing equations of dense phase in the EMMS-based two-fluid model derived from continuum mechanics viewpoint corresponds to the macroscopic transport equations at ( r , t ) space. Therefore, present study launches a solid microscopic foundation of EMMS-based two-fluid model. Finally, CFD simulations have been carried out to validate EMMS-based two-fluid model and to study the effect of gas phase pseudo-turbulence.

      PubDate: 2016-09-18T13:44:25Z
      DOI: 10.1016/j.ces.2016.09.012
      Issue No: Vol. 156 (2016)
  • Water expandable polystyrene containing cellulose nanofibrils: Expansion
           behavior and morphology
    • Authors: Nasser Nikfarjam; Mahmoud Hemmati; Yulin Deng; Nader Taheri Qazvini
      Pages: 56 - 63
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): Nasser Nikfarjam, Mahmoud Hemmati, Yulin Deng, Nader Taheri Qazvini
      Here, we reported a new type of water expandable polystyrene (WEPS) beads containing cellulose nanofibrils (CNFs). This expansible material, called CNFWEPS, showed the highest expansion ratio (~16) for the as-synthesized beads and ~8 after 4.5 months, which has never been reported in the literature. Expandable beads containing 9–13wt% of the well-dispersed water were synthesized through Pickering emulsion polymerization of styrene in the presence of CNF. During the polymerization, CNFs rearrange and create nanospheres which entrap water inside polystyrene beads. Morphological investigations along with thermogravimetric analysis showed that the entrapped water is either discrete water droplets of 9–10µm in diameter or bound water with a strong adsorption to the hydrophilic nanoparticles inside the beads. Importantly, the bound water could be preserved several months after synthesis and therefore prolong the shelf-life of the CNFWEPS beads. The analysis of the expansion kinetics of the CNFWEPS beads revealed three-regime behavior with strong temperature dependency. The highest expansion ratio was obtained at 135°C for the sample containing 0.2wt% of CNF. Overall, apart from stabilization of water in the beads, the vital role of CNF unveiled to be reinforcing the foam structure and inhibiting the cell wall rupture by increasing melt strength of the matrix during expansion.
      Graphical abstract image

      PubDate: 2016-09-18T13:44:25Z
      DOI: 10.1016/j.ces.2016.09.006
      Issue No: Vol. 156 (2016)
  • DEM simulation on the packing of fine ellipsoids
    • Authors: J.Q. Gan; A.B. Yu; Z.Y. Zhou
      Pages: 64 - 76
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): J.Q. Gan, A.B. Yu, Z.Y. Zhou
      In this work, discrete element method (DEM) is used to study the effect of particle size and aspect ratio on packing structure of fine ellipsoids. It shows that porosity and coordination number significantly change with particle size and shape. The porosity-aspect ratio curve has minima at around 0.5 for oblate spheroids and 1.5 for prolate spheroids, but the cusp at 1.0 varies from convex to concave when particle size reduces as a result of the increasing role of the cohesive forces between particles. The coordination number-aspect ratio curves change from a strong to weak “M” shape when particle size reduces. Based on the results, equations are formulated to describe the correlation between bed porosity, aspect ratio, and particle size or force ratio. Microscopically, the radial distribution function is also affected by both particle size and shape. Fine particles have more disordered structure than coarse particles, and the packing of fine spheres is more ordered than fine ellipsoids. For coarse ellipsoids, majority of particles tend to orient horizontally, but the preferred orientation become worse when reducing particle size.

      PubDate: 2016-09-23T17:46:39Z
      DOI: 10.1016/j.ces.2016.09.017
      Issue No: Vol. 156 (2016)
  • Energy efficiency limits in Photo-CREC-Air photocatalytic reactors
    • Authors: Cristina S. Lugo-Vega; Benito Serrano-Rosales; Hugo de Lasa
      Pages: 77 - 88
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): Cristina S. Lugo-Vega, Benito Serrano-Rosales, Hugo de Lasa
      Efficiencies in photocatalytic reactors for air treatment have to be established on the basis of Quantum Yields (QY) and Photochemical Thermodynamic Efficiency Factors (PTEFs) using rigorous methods. This involves the evaluation of absorbed photons on the TiO2 using macroscopic balances. These balances have to account for the incident, the reflected and the transmitted radiation. Moreover, hydroxyl radical formation enthalpy is required for PTEF calculations. This proposed methodology is illustrated in the present study using a spray immobilized photocatalyst in a Photo-CREC-Air unit. The operation of this unit with acetaldehyde model compounds provides high and promising maximum QYs of 124%. These experimentally measured QYs are close to the 133% QY anti cipated theoretical limit. Regarding maximum PTEFs, they were 24%, for acetaldehyde, showing a high degree of photonic energy utilization. Results obtained also allow one to establish the energy required for reacting hydroxyl radical formation, key species for converting organic molecules in photocatalysis. These energy demands affect photoconversion rates and efficiency factors, as observed for acetone and acetaldehyde. Results obtained also demonstrate the special value of experimentally established macroscopic balances. Macroscopic balances allow decoupling photocatalyst efficiency and photoreactor efficiency. This approach is critical to clarify key engineering issues for scaling up photocatalytic reactors.
      Graphical abstract image

      PubDate: 2016-09-23T17:46:39Z
      DOI: 10.1016/j.ces.2016.08.038
      Issue No: Vol. 156 (2016)
  • Degradation of chloroform by Fenton-like treatment induced by
           electromagnetic fields: A case of study
    • Authors: J. Rodríguez-Chueca; A. Mediano; N. Pueyo; I. García-Suescun; R. Mosteo; M.P. Ormad
      Pages: 89 - 96
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): J. Rodríguez-Chueca, A. Mediano, N. Pueyo, I. García-Suescun, R. Mosteo, M.P. Ormad
      The objective of this study of chloroform degradation by the first time through Fenton-like processes induced by electromagnetic fields. Fenton-like processes were carried out at natural pH with 25mg/L of H2O2 and different iron sources: i) FeCl3·6H2O (5, 50 and 100mg/L Fe3+); ii) magnetite (1g/L); iii) clay (80g/L). These treatments were driven in absence and presence of radiofrequency (RF) with an intensity of electromagnetic field of 3.68kA/m. Aqueous solution of chloroform (CHCl3) was also used to study which oxidant species are responsible for the degradation of organic matter. Because of chloroform is scavenger of primary superoxide radicals (•O2 −.) and required of hydroxyl radical for their total degradation. Initial assays of ferromagnetic material/H2O2/RF processes achieved promising results in terms of DOC removal. The highest DOC removal yield (69%) in the treatment of an aqueous solution of CHCl3 was obtained by Fenton/RF treatment using 100mg/L of Fe(III) and 25mg/L of H2O2. In addition, the combination of Magnetite and Fe(III) reached notable values of CHCl3 degradation. The synergetic effect caused by the ferromagnetic properties of Magnetite and the coagulation-flocculation effect caused by iron salts at natural pH is able to reduce the organic matter in water samples. Furthermore, this treatment can be intensified by induction of RF reaching 63% of DOC removal in the CHCl3 solution.
      Graphical abstract image

      PubDate: 2016-09-23T17:46:39Z
      DOI: 10.1016/j.ces.2016.09.016
      Issue No: Vol. 156 (2016)
  • Residence time calculations for complex swirling flow in a combustion
           chamber using large-eddy simulations
    • Authors: A.S. Doost; F. Ries; L.G. Becker; S. Bürkle; S. Wagner; V. Ebert; A. Dreizler; F. di Mare; A. Sadiki; J. Janicka
      Pages: 97 - 114
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): A.S. Doost, F. Ries, L.G. Becker, S. Bürkle, S. Wagner, V. Ebert, A. Dreizler, F. di Mare, A. Sadiki, J. Janicka
      In order to appraise the residence time calculation for a fluid element within a complex combustion system, which features oxy-fuel combustion, large-eddy simulations (LES) are carried out under cold flow conditions in a complex swirled flow generic laboratory-scaled combustor. The quantities, like residence time distribution, mean residence time, cumulative distribution function, variance and skewness, are used to characterize the configuration under investigation. To accurately account for the influence of the flow and to capture the tracer concentration evolution, LES are first assessed by comparison with statistical moments from experiments and by various indices of quality and error analysis. They show that the investigated configuration features a non-ideal reactor based on the flow and tracer transport. The calculated residence time distribution is analyzed and compared with experimental findings providing an estimated mean residence time of about τ=1.9s. The derived residence time and functions are afterwards used to make predictions of tracer concentration at the reactor outlet. It turns out that such an appraised LES methodology is able to capture the residence time distribution in an accurate manner which allows its further extension to reacting conditions.

      PubDate: 2016-09-23T17:46:39Z
      DOI: 10.1016/j.ces.2016.09.001
      Issue No: Vol. 156 (2016)
  • A single particle model of lime sulphation with a fractal formulation of
           product layer diffusion
    • Authors: Fabio Montagnaro; Marco Balsamo; Piero Salatino
      Pages: 115 - 120
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): Fabio Montagnaro, Marco Balsamo, Piero Salatino
      A fractal-like formulation of the random pore model (RPM) is proposed for the reaction of a gas with a solid, with the rate controlled by both diffusion in the layer of solid product and the kinetics of reaction. This approach gives a time-dependent diffusivity in the product. The model’s predictions are compared with measurements of the removal of SO2 with limestone, carried out in a lab-scale fluidized bed reactor. The fractal-like RPM described the production of CaSO4 better than the standard RPM, which overestimated the uptake of SO2 in the first 40min. The decrease of diffusivity in the product layer with time was ascribed to the degree of crystallization of the product, CaSO4, increasing with time and resulting in a lower ionic mobility in its lattice. The equation proposed is a simple and general one for a gas reacting with a solid (alternative example: the carbonation of lime), whose microstructural properties change significantly with the extent of reaction.

      PubDate: 2016-09-23T17:46:39Z
      DOI: 10.1016/j.ces.2016.09.021
      Issue No: Vol. 156 (2016)
  • Molecular simulation of displacement of shale gas by carbon dioxide at
           different geological depths
    • Authors: Haibo Zhang; Dapeng Cao
      Pages: 121 - 127
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): Haibo Zhang, Dapeng Cao
      The rising worldwide energy demand has greatly stimulated the exploitation of shale gas. Meantime, global warming mainly caused by CO2 emission is a significant concern. As a new scenario, injecting CO2 to displace shale gas is proposed to improve the exploitation efficiency of shale gas and reduce the amount of CO2 emission. In this work, we use a grand canonical Monte Carlo simulation to investigate the displacement of shale gas by CO2 and the sequestration of CO2 simultaneously in a modeled shale matrix at different geological depths from 1 to 4km, where the shale is modeled by inorganic clay mineral and organic matter. We find that both the displacement amount of CH4 and the sequestration amount of CO2 increase with the pore size of the shale at a fixed CO2 injection pressure, which suggests that the hydro-fracturing technology would be very beneficial for displacement exploitation of shale gas. Moreover, we also find that the optimum operating condition for CO2 displacing shale gas is at the depth of 1km, which provides a guidance and reference for displacement exploitation of shale gas by CO2.
      Graphical abstract image

      PubDate: 2016-09-23T17:46:39Z
      DOI: 10.1016/j.ces.2016.09.002
      Issue No: Vol. 156 (2016)
  • Improvement of oxygen flux through perovskite membranes using a coating of
           ultra-divided particles
    • Authors: L. Guironnet; P.-M. Geffroy; N. Richet; T. Chartier
      Pages: 128 - 135
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): L. Guironnet, P.-M. Geffroy, N. Richet, T. Chartier
      In the last decades, numerous mixed ionic and electronic conducting materials with a perovskite structure have been investigated for their potential applications as membrane materials for oxygen separation applications. This work shows that significant improvement of electrochemical properties of two perovskite materials, La0.6Sr0.4Fe0.8Co0.2O3-δ (LSFCo6482) and La0.5Sr0.5Fe0.7Ga0.3O3-δ (LSFG5573) is obtained using ultra-divided particles perovskite coating. This coating is obtained by dip-coating thanks to a derived sol-gel synthesis route. The ultra-divided particles have a grain size distribution from 300 to 500nm. The oxygen flux measured using a specific setup shows that the oxygen surface exchange kinetics and bulk diffusion coefficient depend on the microstructure and the chemical composition of the coating material. The relation established between chemical formulation, microstructure, and oxygen flux were used to design optimized membranes.

      PubDate: 2016-09-23T17:46:39Z
      DOI: 10.1016/j.ces.2016.09.019
      Issue No: Vol. 156 (2016)
  • Modeling SO2 absorption into water accompanied with reversible reaction in
           a hollow fiber membrane contactor
    • Authors: Hesheng Yu; Jesse Thé; Zhongchao Tan; Xianshe Feng
      Pages: 136 - 146
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): Hesheng Yu, Jesse Thé, Zhongchao Tan, Xianshe Feng
      The authors developed an efficient flue gas desulfurization (FGD) process employing a hydrophobic polypropylene hollow fiber membrane contactor (HFMC) using deionized water as scrubbing liquid. A novel mathematical reactor model for gas absorption accompanied by a reversible reaction in an HFMC was developed for the first time. This new model employed the resistance-in-series theory, along with partial pore wetting, and a chemical enhancement factor for an instantaneous reversible reaction. This model was validated agreeably with experimental data. The validated reactor model was then employed to investigate the resistance distribution along the main axis and the effects of temperature on SO2 removal efficiency. It was shown that the reactor model with the assumption of non-wetted pores overestimated the absorption efficiency, and a wetted pore length between 6.25–9.75% would yield a very good agreement with the experimental data. The deviations between the predicted and experimental values were less than ±3.0% with an exception of 3.4% at the highest gas rate for gas flow rates ranging from 1.38 × 10 − 4 to 3.01 × 10 − 4 m3 s−1, liquid flow rates between 3.00 × 10 − 6 − 8.00 × 10 − 6 m3 s−1, and the inlet SO2 concentration of 2000 ppmv. Furthermore, the reactor model described the impact of inlet SO2 concentration on the SO2 removal efficiency within ±0.5% of measured values for liquid rates between 4.35 × 10 − 6 and 5.50 × 10 − 6 m3 s− 1 under a gas flow rate of 1.90 × 10 − 4 m3 s− 1. The resistances of shell side, fiber side and membrane are all important due to high solubility of SO2 and partial pore wetting. The SO2 removal efficiency decreased gradually as the temperature increased from 283 to 333K based on model predictions.
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      PubDate: 2016-10-04T09:54:44Z
      DOI: 10.1016/j.ces.2016.09.020
      Issue No: Vol. 156 (2016)
  • Experimental study of the hydrodynamic behaviour of slug flow in a
           horizontal pipe
    • Authors: M. Abdulkadir; V. Hernandez-Perez; I.S. Lowndes; B.J. Azzopardi; E. Sam-Mbomah
      Pages: 147 - 161
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): M. Abdulkadir, V. Hernandez-Perez, I.S. Lowndes, B.J. Azzopardi, E. Sam-Mbomah
      This paper investigates the unsteady hydrodynamic behaviour of slug flow occurring within an air–silicone oil mixture, within a horizontal 67mm internal diameter pipe. A series of slug flow regime experiments were performed for a range of injected air superficial velocities (0.29–1.4ms−1) and for liquid flows with superficial velocities of between 0.05–0.47ms−1. A pair of Electrical Capacitance Tomography (ECT) probes was used to determine: the slug translational velocities of the elongated bubbles and liquid slugs, the slug frequencies, the lengths of elongated bubbles and the liquid slugs, the void fractions within the elongated bubbles and liquid slugs. The pressure drop experienced along the pipe was measured using a differential pressure transducer cell (DP cell). A comparative analysis of the current experimental data and that previously published experimental confirms good agreement.

      PubDate: 2016-10-04T09:54:44Z
      DOI: 10.1016/j.ces.2016.09.015
      Issue No: Vol. 156 (2016)
  • From single drop coalescence to droplet swarms – Scale-up considering
           the influence of collision velocity and drop size on coalescence
    • Authors: Johannes Kamp; Matthias Kraume
      Pages: 162 - 177
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): Johannes Kamp, Matthias Kraume
      Coalescence modelling in liquid/liquid dispersions is a challenging task and field of investigations up to now, which becomes apparent when comparing the various existent models with their different and partly even contradictive implementation of influencing factors. In this work, systematic investigations of single drop coalescence were used to compare and validate different coalescence efficiency models regarding the important influencing parameters relative collision velocity and drop size. The impact of these parameters could be analysed independently from each other for the first time and used to identify the best modelling approach. Moreover, the numerical parameter of the coalescence efficiency model could be obtained based on single drop experiments. Using this determined parameter the simulation of drop size distributions within a lab scale stirred vessel was possible. The presented method offers the possibility of independent parameter estimation for population balance equation simulations based on single drop experiments. The application of this systematic approach allows the separate validation of submodels and reliable parameter determination by small scale investigations. On this basis a sound scale-up is possible using population balance equation simulations.
      Graphical abstract image

      PubDate: 2016-10-04T09:54:44Z
      DOI: 10.1016/j.ces.2016.08.028
      Issue No: Vol. 156 (2016)
  • Fabrication of ternary hierarchical nanofibers MnO2/PANI/CNT and theirs
           application in electrochemical supercapacitors
    • Authors: Wenjie Liu; Shishuang Wang; Qianhui Wu; Long Huan; Xiue Zhang; Chao Yao; Ming Chen
      Pages: 178 - 185
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): Wenjie Liu, Shishuang Wang, Qianhui Wu, Long Huan, Xiue Zhang, Chao Yao, Ming Chen
      In this article, ternary coaxial hierarchical nanofibers are prepared by a simple, repeatable, and scalable method. Polyaniline (PANI) is in-situ polymerized on multiwalled carbon nanotubes (MWCNT) to form PANI/MWCNT. Subsequently, manganese dioxide (MnO2) in-situ grows on PANI/MWCNT nanofibers to form ternary hierarchical nanofibers MnO2/PANI/MWCNT. The electrochemical performance of MnO2/PANI/MWCNT is investigated using cyclic voltammetry (CV), galvanostatic charge-discharge measurement, and electrochemical impedance spectroscopy. The results show that as-prepared ternary hierarchical nanofibers are all typical pseudo-capacitance capacitors. Compared with MWCNT, PANI nanofibers, and PANI/MWCNT composite nanofibers, the specific capacitance of MnO2/PANI/MWCNT composites exhibits the highest capacitance of 348.5Fg−1 at 1Ag−1, and 88.2% of which can still be maintained after 2000 consecutive cycles. The electrochemical measurements demonstrate that PANI layer and nanoflaky MnO2 can increase the specific capacitance of MWCNT. More important, MnO2 in-situ growth on PANI layer can effectively retain the structure of composites and improve the long-term cycle stability, which is conducive to obtain the new-type portable energy storage devices.
      Graphical abstract image

      PubDate: 2016-10-04T09:54:44Z
      DOI: 10.1016/j.ces.2016.09.025
      Issue No: Vol. 156 (2016)
  • Comparative performance of in-line rotor-stators for deagglomeration
    • Authors: N. Gül Özcan-Taşkın; Gustavo A. Padron; Dominik Kubicki
      Pages: 186 - 196
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): N. Gül Özcan-Taşkın, Gustavo A. Padron, Dominik Kubicki
      In-line rotor-stators are used for a wide range of power intensive dispersion applications, including the breakup of immiscible liquid droplets or agglomerates. This study, performed within the DOMINO project at BHR Group, aimed at studying the performance of three different rotor-stator head designs for deagglomeration processes. A given test system, nanoscale silica particles-in-water, was used to identify the mechanism and kinetics of break-up and determine the smallest attainable size. Three rotor-stator head designs used were the GPDH-SQHS and EMSC screens from Silverson and Ytron Z-Lab from Ytron. These in-line rotor-stators were used in the recirculation loop of a stirred tank with a total dispersion volume of 100l. Power input and residence time were varied by changing the rotor speed and dispersion flow rate. Breakup was found to occur through erosion regardless of the operating conditions or rotor-stator design. The smalleachieves a higher fraction of finesst fragments obtained were aggregates, rather than primary particles, and these were of a mean diameter of 150–200nm; also independent of the operating conditions or rotor-stator head design. With a given rotor-stator operated at a given flow rate, increasing the rotor speed and hence the power input increased the break up kinetics. For a given design at a given specific power input, whilst the break up rate per tank turnover decreased when the flow rate was increased, the total processing time could be reduced. There were differences in the volume of the mixer head and chamber volumes; in addition, a smaller flow rate range could be covered with the Ytron design. Comparison of the different designs was therefore not straightforward. It could however be shown that the rotor-stator designs with a high number and small size of holes and/or gaps have a faster break up rate.

      PubDate: 2016-10-04T09:54:44Z
      DOI: 10.1016/j.ces.2016.09.023
      Issue No: Vol. 156 (2016)
  • Formulation and processing of recycled-low-density-polyethylene-modified
           bitumen emulsions for reduced-temperature asphalt technologies
    • Authors: A.A. Cuadri; C. Roman; M. García-Morales; F. Guisado; E. Moreno; P. Partal
      Pages: 197 - 205
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): A.A. Cuadri, C. Roman, M. García-Morales, F. Guisado, E. Moreno, P. Partal
      Sustainable asphalt technologies involving materials recycling and energy-saving approaches are growing demands. Among waste polymers, recycled low density polyethylene (LDPER) is a promising bitumen modifier. Technological and viscous flow tests showed enhanced performance in LDPER-modified bitumens (PMBs) above 4wt% polymer. However, 4wt% LDPER underwent phase separation within 1h when PMB was stored at high temperature, affecting product industrial implementation. Aiming at preventing polymer separation and promoting energy-saving technologies, bituminous binders (containing 2–5wt% LDPER) were successfully dispersed as oil-in-water emulsions (O/W) by an inline emulsification procedure at controlled temperature and pressure. Emulsions with up to 63wt% bitumen phase exhibited broad droplet size distributions and non-Newtonian flow behaviors strongly affected by the emulsion and PMB formulations. Optical and calorimetric techniques conducted on emulsion bituminous residues showed that shear conditions during emulsification increased dispersion of the swollen polymer phase, which led to better properties than the parent PMBs at high in-service temperature.

      PubDate: 2016-10-04T09:54:44Z
      DOI: 10.1016/j.ces.2016.09.018
      Issue No: Vol. 156 (2016)
  • Coupled electromagnetics, multiphase transport and large deformation model
           for microwave drying
    • Authors: Tushar Gulati; Huacheng Zhu; Ashim K. Datta
      Pages: 206 - 228
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): Tushar Gulati, Huacheng Zhu, Ashim K. Datta
      The present work involves development of a fundamentals-based coupled electromagnetics, multiphase transport and large deformation model to understand microwave drying of a hygroscopic porous material. Microwave drying is carried out in a 950W domestic microwave oven operating at 10% power level. Electric field distribution inside the oven cavity and porous material are obtained by solving Maxwell's equations for electromagnetics. Modes of fluid transport include capillarity, binary diffusion and gas pressure-driven flow. Large deformation, included by treating the solid as hyperelastic, is implemented in a novel way using the Arbitrary-Lagrangian–Eulerian framework for mesh movement. Deformation during microwave drying was found to critically alter material structure that significantly affected microwave absorption, heat and moisture transport within the material. Sensitivity analysis revealed that moisture loss and volumetric shrinkage were unaffected with changes in intrinsic permeability and elastic modulus of the material while stress state within the material was highly sensitive to elastic modulus values.

      PubDate: 2016-10-04T09:54:44Z
      DOI: 10.1016/j.ces.2016.09.004
      Issue No: Vol. 156 (2016)
  • Trajectory analysis of a liquid filament under Rayleigh breakup conditions
           created from laminar rotary spraying of oil-in-water emulsions
    • Authors: William R. Case; Franz X. Tanner; Kathleen Feigl; Erich J. Windhab
      Pages: 229 - 238
      Abstract: Publication date: 15 December 2016
      Source:Chemical Engineering Science, Volume 156
      Author(s): William R. Case, Franz X. Tanner, Kathleen Feigl, Erich J. Windhab
      A liquid jet resulting from the laminar rotary spraying of an oil-in-water emulsion (O/W) with a zero shear viscosity of 60mPas and a surface tension on the order 40mN/m has been studied by means of a high-speed camera. The liquid flow rate and rotational speed of the rotary sprayer are tuned so that the liquid filament breaks up into droplets under Rayleigh breakup conditions. From the high-speed imagery we consider in detail the dominant forces, which define the shape of the liquid jet near the nozzle exit. We use the formation of Rayleigh disturbances as a tracing mechanism across multiple high-speed video frames to determine the role that rotational forces, surface tension, viscous forces and wind resistance play on the shape of the liquid filament as well as the formation of resulting droplets. From this analysis it is determined that rotational forces play the dominant role, thus resulting in a simplified parametric model of the liquid jet trajectory based on the Rossby number only. This model is compared to a previous model defined in the Frenet-Serret frame of reference and shown to be the same under our simplifying assumptions. Image analysis of the liquid filament trajectories shows that the assumptions made in the model are valid under the experimental conditions considered here.

      PubDate: 2016-10-04T09:54:44Z
      DOI: 10.1016/j.ces.2016.09.014
      Issue No: Vol. 156 (2016)
  • Effect of foam processing parameters on bubble nucleation and growth
           dynamics in high-pressure foam injection molding
    • Authors: Vahid Shaayegan; Guilong Wang; Chul B. Park
      Pages: 27 - 37
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Vahid Shaayegan, Guilong Wang, Chul B. Park
      We used an innovative visualization mold to investigate the effect of foam processing parameters on bubble nucleation and growth. This was also done to uncover the mechanisms responsible for cellular structural development in the high-pressure foam injection molding process. The effects of the injection speed, the injection gate geometry, the blowing agent content, the melt flow rate and the use of talc as a heterogeneous nucleating agent on the formation and dynamics of cell bubbles were all explored. In the high-pressure foam injection molding process with a proper packing pressure, the overall cell density did not change with the injection speed nor with the injection gate resistance. However, the cell density increased significantly with the blowing agent's concentration and with a nucleating agent. We also observed the growth mechanism of the bubbles in a confined mold cavity, and concluded that the bubble growth rate decreased as the cell density increased. In addition, the satelliting phenomenon, i.e. bubble nucleation around the previously nucleated cells, was observed. This was due to the induced stress fluctuations in the surrounding melt, which could eventually affect the final cellular structure.

      PubDate: 2016-08-11T04:38:06Z
      DOI: 10.1016/j.ces.2016.07.040
      Issue No: Vol. 155 (2016)
  • Gas–liquid mass transfer in a falling film microreactor: Effect of
           reactor orientation on liquid-side mass transfer coefficient
    • Authors: David Lokhat; Ashveer Krishen Domah; Kuveshan Padayachee; Aman Baboolal; Deresh Ramjugernath
      Pages: 38 - 44
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): David Lokhat, Ashveer Krishen Domah, Kuveshan Padayachee, Aman Baboolal, Deresh Ramjugernath
      Microreactors offer a unique platform for chemical syntheses and have been applied to numerous reaction types including nitrations, fluorinations and hydrogenations. A key feature of falling film microreactors is the comparably large specific surface area they afford compared to conventional reactors. The enhanced heat and mass transfer characteristics can be exploited for rapid and exothermic reactions. Adequate understanding of the mass transfer processes occurring within microchannels is necessary for proper reactor design and optimization. In the current study the influence of reaction plate orientation and gas flowrate on liquid-side mass transfer coefficient was investigated via CO2 absorption experiments. Lower plate angles resulted in lower liquid-side mass transfer coefficients. At higher film velocities the rate of mass transfer was greater. The experimentally determined mass transfer coefficients were at least twice as high as those predicted either by film or penetration theory. The enhancement in mass transfer is suggested to be due to cellular convection in the microchannels. For inclined reaction plates, increasing the gas flowrate had a positive effect on the mass transfer characteristics due to induced fluctuations of the gas–liquid interface.
      Graphical abstract image

      PubDate: 2016-08-11T04:38:06Z
      DOI: 10.1016/j.ces.2016.08.002
      Issue No: Vol. 155 (2016)
  • QMOM-based population balance model involving a fractal dimension for the
           flocculation of latex particles
    • Authors: Mélody Vlieghe; Carole Coufort-Saudejaud; Alain Liné; Christine Frances
      Pages: 65 - 82
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Mélody Vlieghe, Carole Coufort-Saudejaud, Alain Liné, Christine Frances
      An experimental and computational study of agglomeration and breakage processes for fully destabilized latex particles under turbulent flow conditions in a jar is presented. The particle size distribution (PSD) and the fractal dimension of flocs of latex particles were monitored using an on-line laser diffraction technique. A population balance equation (PBE) was adapted to our problem by including the fractal dimension in its formulation as well as in the aggregation and breakage kernels. The quadrature method of moments was used for the resolution. The adjustment of 4 model parameters was then conducted on the first 6 moments of the PSD for various mean shear rates. The model correctly predicts the evolution of the first 6 moments calculated from the experimental PSD. The experimental results were adequately simulated by a single set of adjusted parameters, proving the relevance of the dependency on the fractal dimension and mean shear rate. A sensitivity analysis was performed on two main adjusted parameters highlighting the major roles of (1) the power to which the mean shear rate is raised in the breakage kernel and (2) the sizes of the colliding aggregates in the collision efficiency model. Finally, analytical relations between the sink and source terms of the breakage or aggregation of the PBE were derived and discussed, highlighting interesting features of the PBE model.

      PubDate: 2016-08-11T04:38:06Z
      DOI: 10.1016/j.ces.2016.07.044
      Issue No: Vol. 155 (2016)
  • Synthesis of mesoporous materials SBA-16 with different morphologies and
           their application in dibenzothiophene hydrodesulfurization
    • Authors: Zhengkai Cao; Peng Du; Aijun Duan; Rong Guo; Zhen Zhao; Hong lei Zhang; Peng Zheng; Chunming Xu; Zhentao Chen
      Pages: 141 - 152
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Zhengkai Cao, Peng Du, Aijun Duan, Rong Guo, Zhen Zhao, Hong lei Zhang, Peng Zheng, Chunming Xu, Zhentao Chen
      A series of mesostructured SBA-16 materials with different morphologies were prepared by templating method using triblock copolymer pluronic F127 (EO106PO70EO106) as surfactant and tetraethyl orthosilicate (TEOS) as silicon source. The influences of inorganic salt KCl and the synthesis temperature (temperature of the synthesis process before hydrothermal treatment) from 25 to 55°C on the morphologies of SBA-16 materials were also investigated. The obtained materials were characterized by various techniques, including X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), scanning electron microscope (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption, UV–visible diffuse reflectance spectrum (UV–vis DRS), H2 temperature-programmed reduction (H2-TPR), Raman and X-ray photoelectron spectra (XPS) measurements. The SAXS, SEM and TEM results demonstrated that the SBA-16 materials possessed a body-centred cubic Im3m mesostructure. Five kinds of morphologies were found for the as-prepared SBA-16 materials, while sphere SBA-16 particles were obtained at the synthesis temperatures of 25°C and 30°C; mixed states of decahedral together with sphere were obtained at 38°C; decahedral together with dodecahedral was obtained at 45°C; hexagonal prisms was obtained at 50°C; and tetrakaidecahedron was obtained at 55°C. Moreover, aluminium isopropoxide was incorporated into the SBA-16 materials with a Si/Al molar ratio of 20 through the post-synthesized method, and the corresponding hydrodesulfurization (HDS) activities of NiMo supported catalysts on dibenzothiophene (DBT) were also performed in a micro reactor at T=340°C and P=4MPa with different weight hourly space velocities (WHSV). These NiMo catalysts were denoted as NiMo/S-x. S referred to Al modified SBA-16 supports, and x signified the synthesis temperatures from 25 to 55°C. The synthesis mechanism of SBA-16 exhibiting different morphologies was proposed. Meanwhile, the DBT (500ppm) HDS performance over NiMo/S-50 catalyst exhibited the highest conversion of 95.2% at the WHSV of 20h−1.
      Graphical abstract image

      PubDate: 2016-08-15T02:51:47Z
      DOI: 10.1016/j.ces.2016.08.001
      Issue No: Vol. 155 (2016)
  • Methodology for evaluating modular production concepts
    • Authors: Stefan Sievers; Tim Seifert; Gerhard Schembecker; Christian Bramsiepe
      Pages: 153 - 166
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Stefan Sievers, Tim Seifert, Gerhard Schembecker, Christian Bramsiepe
      A more flexible and efficient production of chemicals is a requirement for further strengthening the competitiveness in the chemical industry. An approach proposed to achieve this is modular plant design. It offers new opportunities for the supply chain and combines production flexibility and efficiency. However, modular facilities are expected to be built at comparably small scales and loss of economy of scale is a major concern. There is a need to know under which conditions a modular plant design is a beneficial option. Addressing this it would be helpful to have a methodology that includes modeling of production scenarios in a holistic way including supply chain and process simulation and thus allowing a meaningful evaluation. For that reason we developed such a methodology, using the F3 factory concept as an example for modular plant design. Demonstrating the methodology's feasibility an exemplary implementation in a software tool was established enabling comparative simulation and evaluation of batch, continuous and the modular F3 factory production. As unique feature supply chain and process simulation is combined in a single software implementation allowing for statistical analysis to automatically evaluate the economic performance of production concepts under different boundary conditions of the process and the supply chain. The incorporation of those boundary conditions is usually not part of process simulation and goes beyond state of the art approaches. In this paper, the methodology implemented will be presented and the application will be demonstrated using two production scenarios as examples. For the examples investigated, it was found that compared to the conventional production concept the modular F3 factory concept is economically robust concerning the choice of design capacity with regard to diverse market conditions.

      PubDate: 2016-08-15T02:51:47Z
      DOI: 10.1016/j.ces.2016.08.006
      Issue No: Vol. 155 (2016)
  • Heterogeneous reactive extraction for isopropyl alcohol liquid phase
           synthesis: Microkinetics and equilibria
    • Authors: Vanessa Walter; Bernhard Pfeuffer; Ulrich Hoffmann; Thomas Turek; Detlef Hoell; Ulrich Kunz
      Pages: 175 - 185
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Vanessa Walter, Bernhard Pfeuffer, Ulrich Hoffmann, Thomas Turek, Detlef Hoell, Ulrich Kunz
      The reaction kinetics for the liquid phase synthesis of isopropyl alcohol (IPA) from propene (P) and water (W) using a macroporous sulfonic acid ion exchange resin as catalyst were determined experimentally in a multiphase CSTR in the temperature range 398K to 433K at 8MPa. This high pressure is necessary to dissolve propene in the aqueous phase and to ensure a liquid or supercritical state of all components. At typical reaction conditions, the reactants form two immiscible phases; the reaction takes place in the water swollen gel phase of the catalysts microspheres. Due to the large excess of water in the gel phase the compositions in the gel phase, in the macropore fluid, and in the catalyst surrounding aqueous phase are assumed to be identical. For temperatures up to 413K the reaction kinetics for the used catalyst size are not influenced by mass transfer resistances within the catalyst matrix. Two reactions, the formation of IPA and the condensation reaction of two IPA molecules forming the by-product diisopropyl ether (DIPE), are investigated. The experimental results can be described sufficiently by pseudo-homogeneous rate expressions in aqueous phase activities. For the formation of IPA, the forward reaction is first-order in propene and water while the reverse reaction is first-order in IPA. The activation energy of the forward reaction was determined to 115.3kJ/mol. The formation of DIPE is second order with respect to the activity of IPA. The reverse reaction is first order with respect to the activities of DIPE and water. The activation energy was determined to 85.6kJ/mol. Simultaneous chemical and phase equilibria were investigated theoretically using the volume translated Peng-Robinson equation of state (VTPR-EoS) in combination with a g E-mixing rule. Parameters of the used g E-model were adjusted to experimental liquid-liquid equilibrium (LLE) data.

      PubDate: 2016-08-15T02:51:47Z
      DOI: 10.1016/j.ces.2016.08.005
      Issue No: Vol. 155 (2016)
  • Modeling the change in particle size distribution in a gas-solid fluidized
           bed due to particle attrition using a hybrid artificial neural
           network-genetic algorithm approach
    • Authors: Amir Abbas Kazemzadeh Farizhandi; Han Zhao; Raymond Lau
      Pages: 210 - 220
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Amir Abbas Kazemzadeh Farizhandi, Han Zhao, Raymond Lau
      Particle size distribution (PSD) is an important parameter in gas-solid fluidized bed. The change in PSD due to particle attrition can affect the long-term performance of fluidized bed. In this study, artificial neural network (ANN) with genetic algorithm (GA) as a meta-modeling tool was employed to model the change in PSD during fluidization. Experiments were conducted using incineration bottom ash (IBA) as the fluidizing particles and different mass percentage of large and small glass beads were used as the grinding medium. Rosin–Rammler (RR) distribution was used to describe the IBA PSD. The ANN-GA models developed were subsequently used to study the effect of fluidization time, mass percentage of glass beads and size of glass beads used on the IBA particle attrition during fluidization.
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      PubDate: 2016-08-19T13:06:16Z
      DOI: 10.1016/j.ces.2016.08.015
      Issue No: Vol. 155 (2016)
  • Fluid and particle coarsening of drag force for discrete-parcel approach
    • Authors: Ali Ozel; Jari Kolehmainen; Stefan Radl; Sankaran Sundaresan
      Pages: 258 - 267
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Ali Ozel, Jari Kolehmainen, Stefan Radl, Sankaran Sundaresan
      Fine-grid Euler–Lagrange simulations of gas-fluidization of uniformly sized particles have been performed in three-dimensional periodic domains. Snapshots obtained from these simulations have been systematically coarse-grained to extract filter size dependent corrections to the drag law that should be employed in coarse Euler–Euler (EE) simulations. Correction to the drag law that should be employed in Coarse Multi-Phase Particle-in-Cell (MP-PIC) model simulations is examined through a two-step process: separating the coarsening of the fluid and particle phases. It is found that the drag correction is almost entirely due to the coarsening of the fluid cells, with particle coarsening having only a weak effect. It is shown that drag correction for coarse EE and MP-PIC simulations are comparable. As a result, coarse drag models developed for EE simulations can serve as a good estimate for corrections in MP-PIC simulations, and vice versa.
      Graphical abstract image Highlights fx1

      PubDate: 2016-08-19T13:06:16Z
      DOI: 10.1016/j.ces.2016.08.014
      Issue No: Vol. 155 (2016)
  • Computer virtual experiment on fluidized beds using a coarse-grained
           discrete particle method—EMMS-DPM
    • Authors: Liqiang Lu; Ji Xu; Wei Ge; Guoxian Gao; Yong Jiang; Mingcan Zhao; Xinhua Liu; Jinghai Li
      Pages: 314 - 337
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Liqiang Lu, Ji Xu, Wei Ge, Guoxian Gao, Yong Jiang, Mingcan Zhao, Xinhua Liu, Jinghai Li
      Virtual process engineering (VPE) aims to redefine the roadmap for process scaling-up and optimization, from stepwise experiments to high-performance computer simulations. This is a long-cherished dream of chemical engineers, but requires high standards of Accuracy (the agreement between the simulation and the real process), Capability (the computational speed, scale, and resolution of the simulation), and Efficiency (cost-effective and easy to use), in short, ACE. For complex processes such as gas–solid fluidization, the gap between state-of-the-art simulations and VPE is still huge in terms of ACE. However, the work reported in this paper narrows this gap significantly. In this study, a coarse-grained discrete particle method (DPM) defined by the energy-minimization multi-scale (EMMS) model is deployed for high-resolution simulations of fluidized beds, with the gas- and solid-phase equations solved concurrently by CPUs and GPUs in a heterogeneous supercomputing system. With systematic optimization of the model, numerical method, software, and hardware, we are able to simulate lab- to pilot-scale fluidized beds at quasi-realtime speed, and conduct virtual experiments on such systems. This enables very-long-time simulations to obtain important engineering parameters such as the particle residence time distribution, attrition and deactivation indexes. This work demonstrates that the industrial application of VPE is almost on the horizon.
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      PubDate: 2016-08-24T13:10:30Z
      DOI: 10.1016/j.ces.2016.08.013
      Issue No: Vol. 155 (2016)
  • Novel C-PDA adsorbents with high uptake and preferential adsorption of
           ethane over ethylene
    • Authors: Xingjie Wang; Ying Wu; Xin Zhou; Jing Xiao; Qibin Xia; Haihui Wang; Zhong Li
      Pages: 338 - 347
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Xingjie Wang, Ying Wu, Xin Zhou, Jing Xiao, Qibin Xia, Haihui Wang, Zhong Li
      In this work, a novel porous carbon-based material C-PDA(Carbonized Polydopamine Adsorbent) was prepared using one-step synthesis method for adsorption separation of C2H6/C2H4, and then characterized by N2 adsorption at 77K, FTIR, XPS and TG. The BET surface area and pore volume of C-PDAs can reach as high as 3291m2/g and 1.97 m3/g, respectively. FTIR spectra suggested the presence of N/O functionalities in C-PDAs, and its contents decreased with the KOH/C ratio at which the samples were prepared. Adsorption capacity of C-PDAs for C2H6/C2H4 increased with the surface N and O contents of C-PDAs. More interestingly, it showed significantly preferential adsorption of C2H6 over C2H4. Its C2H6 adsorption capacity was up to 7.93mmol/g at 100kPa, and its C2H6/C2H4 adsorption selectivity was in the range of 1.9–7.94 at pressure below 100kPa when the ratio of C2H6:C2H4 was 0.1:0.9 at 298K, higher than most reported adsorbents possessing preferential adsorption of C2H6 over C2H4. The preferential adsorption mechanism of C2H6 over C2H4 on C-PDAs were revealed by DFT (Density functional theory) calculation. The isosteric heat of C2H6 and C2H4 adsorption on C-PDAs were much lower than the preferential adsorption affinity of olefin over π-complexation sorbents. These excellent adsorption properties of C-PDAs make it a type of promising adsorbent for the effective separation of ethane/ethylene.
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      PubDate: 2016-08-24T13:10:30Z
      DOI: 10.1016/j.ces.2016.08.026
      Issue No: Vol. 155 (2016)
  • Engineered polymeric nanoparticles of Efavirenz: Dissolution enhancement
           through particle size reduction
    • Authors: B.N. Vedha Hari; Cui-Lin Lu; N. Narayanan; Rui-Rui Wang; Yong-Tang Zheng
      Pages: 366 - 375
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): B.N. Vedha Hari, Cui-Lin Lu, N. Narayanan, Rui-Rui Wang, Yong-Tang Zheng
      Solubility and bioavailability of drug molecules are the key factors influencing their therapeutic effectiveness in-vivo. The desired drug concentration in systemic circulation can be achieved through the required dissolution of the drug in the biological environment which ultimately affects the pharmacological response. Efavirenz is an anti-HIV molecule with low solubility and variable bioavailability (<45%) and prescribed as first line drug with 800mg dose. The objective of the study was to develop polymeric nanoparticles of Efavirenz and assess the dissolution enhancement, safety and efficacy using T-lymphatic cell lines infected with HIV-1IIIB strain. The nanoparticle formulations were developed using solvent evaporation method and characterized for its size (110–283nm), charge (−21 to −33mV), % entrapment efficiency (57–95%), viscosity of nanosuspension (2.39–4.2cP) and surface area of the particles (1.4m2/g). The fourier transform infrared analysis and differential scanning calorimetry analysis of the pure drug and nanoparticles revealed the compatibility and stability of drug in nanoparticles. The in-vitro dissolution studies of the nanoparticles in distilled water media using type-1 USP dissolution apparatus at 100rpm showed improved drug release based on the polymer composition, as compared with marketed formulations (capsules). The cytotoxicity and therapeutic activity of nanoparticles was studied by MTT assay in C8166 cell lines and syncytium formation assay using HIV-1IIIB strain infected cell lines, respectively. Cell uptake of the nanoparticles was studied by confocal microscopy. The formulated nanoparticles were found to be safe and exhibiting 2-fold increase in therapeutic activity compared to pure drug, which could be attributed to improved dissolution and high cell uptake.
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      PubDate: 2016-08-24T13:10:30Z
      DOI: 10.1016/j.ces.2016.08.019
      Issue No: Vol. 155 (2016)
  • Incorporation of 10-hydroxycamptothecin nanocrystals into zein
    • Authors: Guijin Liu; Shaomin Li; Yinxia Huang; Hongdi Wang; Yanbin Jiang
      Pages: 405 - 414
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Guijin Liu, Shaomin Li, Yinxia Huang, Hongdi Wang, Yanbin Jiang
      Incorporation of drug nanocrystal (DNC) into a particulate carrier to form the DNC delivery system was conducted in this study, where 10-hydroxycamptothecin (HCPT) was selected as the model drug and zein was the carrier. The supercritical anti-solvent (SAS) process or the built-in ultrasonic dialysis process (BUDP) was applied to prepare HCPT NC-loaded zein microspheres (HCPT NC-Zein MS) at first respectively, but the results showed that the products obtained were unsatisfactory in their particle microstructures. Fortunately, by combining the SAS process with BUDP, i.e. the co-precipitation of HCPT and zein prepared using the SAS process was dispersed into ethanol–water as the dialysis solution for BUDP, the results showed that desirable HCPT NC-Zein MS were obtained. The formulations were evaluated quantitatively by an overall desirability function (DF), and the optimized HCPT NC- Zein MS was prepared according to the range analysis results of DF. Under the optimized conditions, HCPT NC-Zein MS with a mean particle size=1.10±0.12µm, drug loading=5.98% and encapsulation efficiency=95.68% were obtained. The further characterizations of SEM, FT-IR, XRD and DSC demonstrated that HCPT NC was successfully incorporated into the interior of zein microspheres. The effects of the process parameters and the formation mechanism of HCPT NC-Zein MS were discussed in detail. Furthermore, it is presented that HCPT NC-Zein MS sustained HCPT release rate successfully, where about 50% HCPT was fast released in the first 20h, then the release trend followed zero order kinetics and reached 70% in 82h.
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      PubDate: 2016-08-27T23:38:56Z
      DOI: 10.1016/j.ces.2016.08.029
      Issue No: Vol. 155 (2016)
  • Multiscale modeling and experimental analysis of chemical vapor deposited
           aluminum films: Linking reactor operating conditions with roughness
    • Authors: Ioannis G. Aviziotis; Nikolaos Cheimarios; Thomas Duguet; Constantin Vahlas; Andreas G. Boudouvis
      Pages: 449 - 458
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Ioannis G. Aviziotis, Nikolaos Cheimarios, Thomas Duguet, Constantin Vahlas, Andreas G. Boudouvis
      When composition and crystallographic structure remain constant, film properties mainly depend on microstructure and surface morphology. In this case, the proper modeling of a growing film allows linking the final surface features with the operating conditions at the reactor scale which in turn enables the control of the properties of the final film. In this work, an experimentally supported, coarse-grained, multiscale framework is applied for the modeling of the surface roughness of aluminum thin films processed by chemical vapor deposition from dimethylethylamine alane. The multiscale framework is developed by linking macroscopic transport phenomena based on continuum mechanics models with nanoscale surface events which are simulated stochastically. The model reproduces experimental data successfully, thus validating the method with good statistics. Finally, modeling of surface roughness enables the estimation of the electrical resistivity in good agreement with corresponding measurements.
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      PubDate: 2016-10-04T09:54:44Z
      DOI: 10.1016/j.ces.2016.08.039
      Issue No: Vol. 155 (2016)
  • Modeling simultaneous deposition and aggregation of colloids
    • Authors: Stefano Lazzari
      Pages: 469 - 481
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Stefano Lazzari
      Solid formation and particle deposition in chemical and pharmaceutical processes often leads to heat exchanger or reactor fouling, compromising operability. The aim of this work is to propose a mathematical framework, based on population balance equations, to describe the simultaneous colloid aggregation and deposition. The problem is dealt with by accounting for two distinct cluster mass distributions, the first one describing the free clusters, while the second one the deposited aggregates. Three main events are considered: (i) aggregation of two free clusters, (ii) deposition of free clusters on the reactor wall (i.e. a free cluster turns into a deposited one), and (iii) aggregation of a free cluster with a deposited one. To describe the aggregation of free clusters, three typical aggregation kernels (i.e. diffusion-limited and reaction-limited cluster aggregation as well as simple shear aggregation) have been used. Starting from those kernels, aggregation laws to describe the interaction between a free and a deposited cluster were proposed and a simple cluster-mass dependent deposition law was employed. The simulation results are then discussed in the frame of one dimensionless parameter, function of the relevant characteristic time of the process (i.e. aggregation and deposition).
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      PubDate: 2016-09-11T14:26:39Z
      DOI: 10.1016/j.ces.2016.08.040
      Issue No: Vol. 155 (2016)
  • Experimental methodology for study of granular material flow using digital
           speckle photography
    • Authors: Simon Larsson; Gustaf Gustafsson; Aliae Oudich; Pär Jonsén; Hans-Åke Häggblad
      Pages: 524 - 536
      Abstract: Publication date: 22 November 2016
      Source:Chemical Engineering Science, Volume 155
      Author(s): Simon Larsson, Gustaf Gustafsson, Aliae Oudich, Pär Jonsén, Hans-Åke Häggblad
      Granular material flow occurs in many industrial applications, and the characteristics of such flow is challenging to measure. Therefore, an experimental method that captures the flow behavior at different loading situations is desired. In this work, experimental measurements of granular material flow with digital speckle photography (DSP) are carried out. The granular flow process is recorded with a high-speed camera; the image series are then analyzed using the DSP method. This approach enables field data such as displacement, velocity, and strain fields to be visualized during the granular material flow process. Three different scenarios were studied: free surface flow in a fill shoe, flow without a free surface in a fill shoe, and the rearrangement of material in a cavity. The results showed that it is possible to obtain field data of the motion of particles for all three scenarios with the DSP technique. The presented experimental methodology can be used to capture complex flow behavior of granular material.
      Graphical abstract image Highlights fx1

      PubDate: 2016-09-18T13:44:25Z
      DOI: 10.1016/j.ces.2016.09.010
      Issue No: Vol. 155 (2016)
  • A kinetic inlet model for CFD simulation of large-scale bubble columns
    • Abstract: Publication date: 2 February 2017
      Source:Chemical Engineering Science, Volume 158
      Author(s): Weibin Shi, Ning Yang, Xiaogang Yang
      For the simulation of industrial-scale bubble column reactors, while modelling the gas distributor as uniform inlets oversimplifies the inhomogeneity introduced by inlets, the direct simulation of the full geometry of gas distributor or sparger brings about enormous pre-processing work and huge computational cost. A new inlet model is therefore proposed in this paper to simplify the modelling of gas distributor and meanwhile maintain the simulation accuracy. The new inlet model is validated by the comparison of the model prediction with experiments and the CFD simulation incorporating the full geometry of gas distributor for bubble columns of small or large diameters. Comparisons of three different inlet boundary conditions, i.e., the direct simulation of gas distributor, the uniform inlet, and the new inlet model, are made in the simulation of the total gas holdup, the radial profiles of gas holdup at different cross-sections along the column height, and the axial velocity of liquid at various superficial gas velocities. The results indicate that the new inlet model is capable of achieving a good balance between simulation accuracy and computational cost for the CFD simulation of large-scale bubble column reactors.

      PubDate: 2016-10-16T15:25:41Z
  • Study on “interface – shrinkage – driven” breakup of droplets in
           co-flowing microfluidic devices
    • Abstract: Publication date: 2 February 2017
      Source:Chemical Engineering Science, Volume 158
      Author(s): Wenjie Lan, Shan Jing, Xuqiang Guo, Shaowei Li
      In co-flowing microfluidic device, it is usually thought the droplet size is significantly influenced by the capillary number in dripping flow. However, it was found in this study that when the contact angle of the dispersed fluid with the dispersed fluid channel was sufficiently large, the droplet size would be little affected by the capillary number. To explain this phenomenon, an “interface – shrinkage – driven” breakup mechanism was proposed. Three different systems and six different microfluidic devices were used in the experiment to prove the universality of the mechanism. The critical contact angle of the dispersed fluid with the dispersed fluid channel was finally discussed.

      PubDate: 2016-10-16T15:25:41Z
  • Lignin-derived multi-cyclic high density biofuel by alkylation and
           hydrogenated intramolecular cyclization
    • Abstract: Publication date: 2 February 2017
      Source:Chemical Engineering Science, Volume 158
      Author(s): Genkuo Nie, Xiangwen Zhang, Peijuan Han, Junjian Xie, Lun Pan, Li Wang, Ji-Jun Zou
      Biofuels are important alternative for fossil-based fuel but they have either relatively low density or high freezing point and viscosity. Here we reported a simple and efficient route to synthesis biofuel with density comparable to widely used JP-10 fuel as well as good low-temperature properties. Substituted diphenyl methane was synthesized by acid catalytic alkylation of lignin-derived phenols (phenol, anisole, guaiacol) with benzyl ether or benzyl alcohols, and MMT-K10 exhibits better activity than HPW, Amberlyst-15, and Al-MCM-41, due to the modest acid strength and open lamellar structure. High selectivity along with good-to-excellent conversion was obtained under optimized conditions regardless of different reactant used. Then the alkylated product was subjected to hydrogenation with the presence of Pd/C and HZSM-5, and interestingly, intramolecular cyclization reaction occurred to produce a large amount of perhydrofluorene as well as dicyclohexylmethane. Subsequently, biofuel with density as high as 0.93g/mL and freezing point as low as −40.0°C was obtained, which surpasses the state-of-art of biofuel reported.
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      PubDate: 2016-10-16T15:25:41Z
  • Heat Exchanger Network Synthesis without stream splits using parallelized
           and simplified simulated Annealing and Particle Swarm Optimization
    • Abstract: Publication date: 2 February 2017
      Source:Chemical Engineering Science, Volume 158
      Author(s): Leandro Vitor Pavão, Caliane Bastos Borba Costa, M.A.S.S. Ravagnani
      Much attention has been paid to heat exchanger network (HEN) synthesis and optimization by using meta-heuristic approaches. In general, Simulated Annealing (SA) is able to provide good solutions, but with large computational efforts. In the present work, a two-level no-split HEN synthesis hybrid method is presented. SA is used for topology optimization, while continuous heat load variables are handled with Particle Swarm Optimization (PSO). SA is simplified and only one type of move is used (single heat exchanger addition), along with group optimizations to improve PSO performance. A parallel processing technique is also presented in order to improve local search performance. The method is tested in 4 medium and large scale benchmark case studies and the no-splits results are compared to literature solutions with and without splits. The solutions presented have lower Total Annual Costs (TAC) when compared to other no-split HENs, and even to some HENs with splits. The proposed method is able to present near-optimal solutions by more efficiently exploring the search space and using simple moves for local searches.

      PubDate: 2016-10-16T15:25:41Z
  • Turbulent spectrum model for drop-breakup mechanisms in an inhomogeneous
           turbulent flow
    • Abstract: Publication date: 2 February 2017
      Source:Chemical Engineering Science, Volume 158
      Author(s): Thierry Lemenand, Dominique Della Valle, Pascal Dupont, Hassan Peerhossaini
      Drop-breakup models for liquid/liquid dispersion in turbulent flow mostly derive from Kolmogorov and Hinze analysis. They are of a semi-empirical type, since they are based on power laws involving at least Weber and Reynolds numbers. The pre-factors are determined by fitting the experimental data on droplet diameters in the various configurations. The main cause for the discrepancies in the fitting constant between different flow types is the intrinsic spatial heterogeneity of the turbulent field, especially the turbulent kinetic energy (TKE) dissipation rate ε. This feature explains why there is no universal physical model suitable for breakup prediction throughout the range of flow geometries. In the present work, we investigate the drop size distribution by reference to Hinze's actual theory in a local approach, attempting a direct interpretation thanks to the turbulence spectra measured (by LDA) in the most dissipative locations of a flow which is basically inhomogeneous. This method allows estimation of droplet size with no constant fitting and with acceptable accuracy; however the knowledge of the turbulence field is required. The present study is carried out with low dispersed-phase fraction, so that the coalescence is negligible. Experiments show that the “typical value” for the TKE dissipation rate to fit the raw model of Hinze and Kolmogorov lies between the maximum and the mean value in the flow field. The issue of “typical ε value” hence avoided is discussed by physical arguments for the flow structure.

      PubDate: 2016-10-16T15:25:41Z
  • Review of cluster characteristics in circulating fluidized bed (CFB)
    • Abstract: Publication date: 2 February 2017
      Source:Chemical Engineering Science, Volume 158
      Author(s): Andy Cahyadi, Aditya Anantharaman, Shiliang Yang, S.B. Reddy Karri, John G. Findlay, Ray A. Cocco, Jia Wei Chew
      Particle clusters are well acknowledged to affect the hydrodynamics and overall performance of gas-solid fluidized beds. Since one of the first reports on the clustering phenomenon in 1948, the understanding of particle clustering has been rigorously attempted via both modeling and experimental efforts, with significant traction gained especially in the last few decades. Accordingly, the current review targets at providing a comprehensive landscape of the experimental cluster trends to summarize the findings, in particular on circulating fluidized bed (CFB) risers, to date. More questions than answers seem to have sprouted from the abundant experimental data available, which impedes model development. The quantitative comparison of cluster characteristics across studies must be treated with caution, because of (i) different riser configurations, instruments and analysis methods, which can lead to discrepancies of an order-of-magnitude; (ii) the impact on cluster characteristics by an interplay of a host of factors, hence the influence of a single parameter is not straightforward, even within the same study; (iii) the irregularity in the form of clusters, hence the definition and/or measurement of the various cluster characteristics differ; and (iv) the general lack in the reporting of the actual particle size distribution. What is remarkable is that the trends of the cluster characteristics are relatively consistent despite different experimentalists and units.

      PubDate: 2016-10-16T15:25:41Z
  • The effect of operating conditions on the residence time distribution and
           axial dispersion coefficient of a cohesive powder in a rotary kiln
    • Abstract: Publication date: 2 February 2017
      Source:Chemical Engineering Science, Volume 158
      Author(s): Ingrid J. Paredes, Bereket Yohannes, Heather Emady, Benjamin J. Glasser, William G. Borghard, Fernando Muzzio, Alberto M. Cuitiño, Jean Beeckman, Samia Ilias, Paul Podsiadlo, Eric Jezek, Joseph Baumgartner
      While continuous rotary calcination is a widely used thermal treatment in large-scale catalyst manufacturing, the process's heat and mass transfer mechanisms remain a challenge to characterize and to predict. Thus, the goal of this research is to improve fundamental understanding of rotary calcination to aid in the creation of a scientific methodology for process design and scale-up. For successful calcination to occur, the residence time of the particles must exceed the time required for heating and calcination at a set temperature. The optimal residence time therefore depends on both of these competing time scales, each of which is function of feed material properties, kiln geometry and kiln operating conditions. For uniform treatment of the feed, the particles must also exhibit low axial dispersion. In this work, the residence time distribution and axial dispersion coefficient for a dry cohesive fluid cracking catalyst powder were measured in a pilot plant kiln using a tracer study developed by Danckwerts. Results were successfully matched to the Taylor fit of the axial dispersion model and the Sullivan prediction for mean residence time. It was found that an increase in feed rate, kiln incline and rotary speed decreased mean residence time and overall axial dispersion. Such results have been established previously for free-flowing material like millimeter-sized extrudates, but have not been previously reported for the cohesive powders such as the one used in our work. As in free-flowing material, the axial dispersion coefficient was found to vary with kiln conditions. The values of the axial dispersion coefficients were lower for the powder than for free-flowing material, showing a dependency of axial dispersion on material properties as well as bulk flow behavior.

      PubDate: 2016-10-16T15:25:41Z
  • Preparation of a non-hydrothermal NaA zeolite membrane and defect
           elimination by vacuum-inhalation repair method
    • Abstract: Publication date: 2 February 2017
      Source:Chemical Engineering Science, Volume 158
      Author(s): Meng-xue Xu, Yan He, Yi-pin Wang, Xue-min Cui
      This work reports the preparation of a non-hydrothermal NaA zeolite and its stainless steel-supported membrane using geopolymer-gel-thermal-conversion (GGTC) combined with a dip-coating method, which does not require hydrothermal processing. The XRD and high-resolution transmission electron microscopy (HRTEM) analyses indicate that the 1.1Na2O–Al2O3–2SiO2–8H2O geopolymer gels cured at 25°C nucleate in the geopolymerization stage. After heat-treatment above 60°C, the crystal nuclei in the geopolymer gels continue to grow and transform into NaA zeolite crystals with good crystallinity. To improve the separation efficiency of the stainless steel-supported NaA zeolite membrane in the pervaporation (PV) process of an ethanol/water mixture, this paper reports a simple vacuum-inhalation repair method for non-zeolitic pores or other defects in the NaA zeolite membrane. After vacuum-inhalation repair of the non-hydrothermal NaA zeolite membrane with sodium alginate solutions and CaCl2 solutions, in that order, the repaired NaA zeolite membrane exhibited a separation factor that was enhanced approximately 7- to 14-fold over that of the unrepaired NaA zeolite membrane.

      PubDate: 2016-10-16T15:25:41Z
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